Retraction devices for the taking up of slack in cord, free-ended chains, cables, string and the like (all of which will be referred to herein as "cord") serve an important safety and convenience function in many fields. The present invention is directed towards a device that has particular application for taking up the cords of window blinds. Such devises may serve an safety important function when used with window blinds, since the long dangling cords of window blinds can pose a hazard to young children. A retraction device for use with window blind cords is preferably adaptable for use with, alternatively, a pair of free-ended cords, as is found in a venetian blind, or a cord loop, as is found in a vertical blind. For use with a cord loop, the retraction device must be capable of allowing the cord to pass freely through the device when in the unretracted position. As well, it is desirable to provide a retraction device that can be readily engaged to a cord, in order for easy attachment to a installed window blind.
While many retraction devices exist for the taking up of cord, these existing devices do not provide an adequate solution to the requirements of window blind cord retraction devices.
Retraction devices typically comprise two elements: a rotatable take-up spool and a spool support. The take-up spool is generally spring loaded, although it may also be rotated by a crank. The spring is typically a coil spring positioned inside the spool, one end thereof being fastened to the perimeter of the spool and the other end being fastened to a central spindle engaged to the spool support. The spool support is generally incorporated into a case, with the cord entering the case through an aperture extending through the wall of the case. There may also be provided spool lock means, to releasably lock the spool in either the wound or unwound position, or any intermediary position.